Quarry dust
The fine stone left by crushing. Block makers mix it with sharp sand for harder, squarer six-inch and nine-inch blocks.
The material
Three-quarter inch is what most engineers mean when they write “granite” on a drawing. It is big enough to give a slab real strength and small enough to pass between the bars of a normal mat of reinforcement.
Ours goes through a jaw crusher and then a cone crusher, which gives it the cubic, angular shape that locks into the cement paste. Rounder river gravel is cheaper, but it slips; angular granite grips.
Before it is loaded, every stockpile is sampled and sieved. Each delivery ticket carries the batch number, so if your engineer wants the test sheet, our lab sends it the same day.
“The workhorse stone of Kano building sites. Clean, angular, single sized granite for slabs, footings and general concrete.”From the Granite Peak spec sheet
Order this material
₦24,500 a tonne
At the weighbridge, example rate. Add haulage by zone. Minimum load ten tonnes.
Specification
The numbers
Typical values from our weekly testing. The test sheet for your batch comes with the delivery ticket. Example data for this demo.
- Nominal size
- 19 mm
- Passing 12.5 mm
- 20 to 55 per cent
- Fines under 75 microns
- under 2 per cent
- Flakiness index
- under 25 per cent
- Bulk density, loose
- about 1.5 t per m³
- Aggregate crushing value
- about 22 per cent, example
In use
Where it goes
The jobs our customers use it for most often.
Ground slabs
At 1 : 2 : 4 with sharp sand, about 1.3 tonnes of chippings per cubic metre of concrete.
Suspended slabs
The standard choice for decks on bungalows and duplexes.
Strip foundations
At 1 : 3 : 6 for blinding and plain footings.
Septic tanks and soakaways
Plain concrete bases and covers.
Photos for this demo.
Questions
Asked at the weighbridge
How many tonnes are in a 30-tonne trailer?
Thirty, weighed on our bridge with the ticket on your phone. A trailer carries about 20 cubic metres of loose chippings.
Is it washed?
It is screened dry, which takes the fines below 2 per cent. Washed chippings are available for precast yards on a two-day order.
Can I mix three-quarter and half inch?
Yes, many engineers ask for a 70 to 30 blend for slabs with tight steel. We blend at the loader for a small fee.
Why is my neighbour paying less?
Price differences usually come from quarry dust mixed into cheap loads. Check the ticket and the sieve sheet.
Related materials
Crushed stone base
A graded mix from 40 mm down to dust that locks together under a roller. The base under estate roads, yards and driveways.
Next step
Size it, book it
Run your site through the calculator, then pick a delivery window. Or call sales on +234 800 000 1011. Example details for this demo.